astro.wikisort.org - Asteroid

21088 Chelyabinsk, provisional designation 1992 BL₂, is a stony asteroid and near-Earth object of the Amor group, approximately 4 kilometers in diameter. It was discovered on 30 January 1992, by Belgian astronomer Eric Elst at ESO's La Silla Observatory in northern Chile. The asteroid was named after the Russian city of Chelyabinsk and for its spectacular Chelyabinsk meteor event in 2013.[2]

21088 Chelyabinsk

Discovery [1]
Discovered by	E. W. Elst
Discovery site	La Silla Obs.
Discovery date	30 January 1992
Designations
MPC designation	(21088) Chelyabinsk
Named after	Chelyabinsk [2] (city and meteor)
Alternative designations	1992 BL2
Minor planet category	NEO · Amor [1][2] Mars-crosser
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	27.41 yr (10,012 days)
Aphelion	2.1135 AU
Perihelion	1.2996 AU
Semi-major axis	1.7065 AU
Eccentricity	0.2384
Orbital period (sidereal)	2.23 yr (814 days)
Mean anomaly	318.92°
Mean motion	0° 26m 31.56s / day
Inclination	38.455°
Longitude of ascending node	297.85°
Argument of perihelion	27.133°
Earth MOID	0.3083 AU · 120.1 LD
Physical characteristics
Dimensions	2.79±0.10 km[3] 3.46±0.25 km[4] 4.23 km (taken)[5] 4.231±0.113 km[6][7] 4.232 km[8]
Synodic rotation period	22.426±0.02 h[lower-alpha 1][lower-alpha 2] 22.49 h[lower-alpha 1]
Geometric albedo	0.1794[8] 0.206[6] 0.257±0.038[4] 0.26±0.32[9] 0.37±0.06[3]
Spectral type	Q [10] · L [11] · S [5] B–V = 0.855±0.073[12] V–R = 0.464±0.015[12]  V–I = 0.910±0.032[12]
Absolute magnitude (H)	13.86±0.14 (R)[lower-alpha 1] · 14.00[11] · 14.2[6] · 14.29±0.24[13] · 14.3[1] · 14.35±0.149[5][8] · 14.40[4]

Classification and orbit

Chelyabinsk orbits the Sun at a distance of 1.3–2.1 AU once every 2 years and 3 months (814 days). Its orbit has an eccentricity of 0.24 and an inclination of 38° with respect to the ecliptic. A first precovery was taken during the Digitized Sky Survey at the Australia Siding Spring Observatory in January 1990, extending the asteroid's observation arc by 2 years prior to its official discovery at La Silla.[2]

Close approaches

As a near-Earth object, Chelyabinsk has a low Earth minimum orbit intersection distance of 0.3083 AU (46,100,000 km), which translates into 120.1 lunar distances (LD). This is, however, far too large to make it a potentially hazardous asteroid, which have intersection distances of less than 20 LD.[1] It also crosses the orbit of Mars at 1.666 AU which makes it a Mars-crossing asteroid. In August 2142, it will approach the Red Planet at 0.0986 AU (14,800,000 km).[1]

Physical characteristics

Chelyabinsk has been characterized as both a Q-type and L-type asteroid.[10][11] It is also a generically assumed S-type asteroid.[5]

Lightcurves

Two rotational light-curves of Chelyabinsk were obtained by Czech astronomer Petr Pravec at Ondřejov Observatory in December 2002 and September 2004, respectively. They gave a rotation period of 22.490 and 22.426 hours, each with a brightness variation of 0.13 magnitude (U=n.a./3-).[lower-alpha 1][lower-alpha 2]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Chelyabinsk measures between 2.79 and 4.2 kilometers in diameter and its surface has an albedo between 0.21 and 0.37,[6][7][8] while observations by the Japanese Akari satellite gave an albedo of 0.26 and a diameter of 3.5 kilometers.[4] The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE results, that is, a diameter of 4.23 kilometers and an albedo of 0.179 based on an absolute magnitude of 14.35.[5][8]

Naming

This minor planet is named after the Russian city Chelyabinsk, located in the Urals, Siberia. The city is well known for the Chelyabinsk meteor, a 20-meter sized, extremely bright fireball that exploded to the south of the city at an altitude of 30 kilometers on 15 February 2013. The indirect effects of the explosion injured more than 1,500 people.[2] The official naming citation was published by the Minor Planet Center (MPC) on 21 August 2013 (M.P.C. 84674).[14]

Erratum

Originally, the name "Chelyabinsk" was erroneously given by the MPC to the numerically similar asteroid (20188) 1997 AC₁₈ on 22 July (M.P.C. 84379). The wrong designation 20188 Chelyabinsk was deleted in the subsequent publication of the Minor Planet Circulars on 21 August 2013 (M.P.C. 84385) [14]

Notes

References

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• 21088 Chelyabinsk at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
• 21088 Chelyabinsk at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical Properties · Summary
• 21088 Chelyabinsk at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

На других языках

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- [en] 21088 Chelyabinsk

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[ru] (21088) Челябинск

(21088) Челябинск (лат. Chelyabinsk) — околоземный астероид из группы Амура (II), который был открыт 30 января 1992 года бельгийским астрономом Эриком Эльстом в обсерватории Ла-Силья и назван в честь Челябинска, крупного промышленного города на Урале.

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